The present invention relates to an air quality monitoring and space and energy management system that uses the infrastructure of a private communications network, and to an air quality sensor for the system.
The typical approach to providing satisfactory air quality in work spaces or living spaces is to measure contaminant concentrations in the space, both in terms of gas or vapor concentrations (i.e., CO, CO2 or other noxious gases), or airborne particulate concentrations. The measured values are then compared with safe or recommended air quality conditions. Measurement of air quality, however, typically requires complex and expensive equipment to be used by specially trained personnel.
The present invention relates to an air quality monitoring and space management system that sends air quality data over the existing private communications network, such as a local area network, at a site. In one embodiment, the air quality data can be uploaded to a second private communications network via a public communications network. The second private communications network provides archiving and data processing functions, such as trend analysis. The second private communications network can also send alerts when an air quality attribute exceeds a predetermined value. Alerts can also be sent if the trend of an air quality attribute is predicted to exceed a predetermined value during a predetermined time sequence. Remote access to the air quality data is provided through the public communications network.
The present air quality monitoring system works in conjunction with a private communications network adapted to carry data traffic at a site. The air quality monitoring system includes at least one sensor assembly programmed to collect air quality data at the site. The sensor assembly includes at least one air quality sensor adapted to measure a level of an air quality attribute. The air quality sensor is coupled to a microprocessor and a data storage device. A communications device couples the microprocessor to the private communications network. A public communications network is coupled to the private communications network. An archiving and processing system at a remote data collection site comprises a controller programmed to automatically acquire over the public communications network air quality data from one or more sensor assemblies and to automatically store air quality data in a database.
The air quality sensors are typically adapted to measure different air quality attributes. Each sensor assembly preferably comprises a sensor assembly identification number. In one embodiment, the air quality data for a particular sensor comprises a format specific to the air quality attribute being measured. The air quality data for a particular site can be associated with a site identification number.
The air quality sensors typically output a voltage signal proportional to a measured level of an air quality attribute. The microprocessor is programmed to convert sensor data to air quality data. In one embodiment, the microprocessor is programmed to convert sensor data to an industrial control protocol. In another embodiment, the microprocessor is programmed to convert sensor data to an industrial control protocol compatible with HVAC equipment. The microprocessor can be coupled to an HVAC controller directly or through the private communications network.
The microprocessor can be programmed to systematically collect air quality data from the air quality sensors at defined intervals and to transmit the air quality data to the private communications network. The microprocessor can also be programmed to systematically collect air quality data from the air quality sensors at defined intervals and to transmit the air quality data over the private communications network and the public communications network to the archiving and processing system. The microprocessor can also be programmed to systematically collect air quality data from the air quality sensors at defined intervals and to store the air quality data in the data storage device. The archiving and processing system is typically a second private communications network coupled to the public communications network.
The data storage device is preferably a read/write semiconductor memory device. The data storage device preferably has sufficient storage capacity to store air quality data for a period of time (e.g., one week). The data storage device can optionally include an error correction table for one or more of the air quality sensors. In one embodiment, the data storage device includes a calibration table for one or more of the air quality sensors. The microprocessor can optionally be programmed to adjust sensor data from a first sensor in response to sensor data collected by a second sensor. In another embodiment, the microprocessor is programmed to modify an error correction table for a first sensor in response to sensor data from a second sensor.
In one embodiment, a heater sensing and control circuit is coupled to the microprocessor. A heater controlled by the heater sensing and control circuit is operatively coupled to one or more temperature dependent sensors. The microprocessor is preferably programmed to calibrate one or more of the temperature dependent sensors. In another embodiment, the microprocessor is programmed to control and adjust one or more heaters adjacent to one or more temperature dependent sensors to maintain an operating temperature within a specified tolerance. In yet another embodiment, the microprocessor is adapted to combine air quality data from two or more air quality sensors to provide an air quality index. Alternatively, the archiving and processing system is adapted to combine air quality data from two or more air quality sensors to provide an air quality index. In another embodiment, the sensor is adapted to provide a relative indication of air quality based upon the presence of a plurality of VOC""s.
In one embodiment, the communications device comprises a semiconductor communications driver. The communications device is preferably programmed to transmit digital data corresponding to the air quality data to the private communications network. In another embodiment, the microprocessor is programmed to convert the sensor data into a protocol compatible with the communications interface and/or the private communications network.
The present system includes remote sites coupled to the database through the public communications network.
In one embodiment, the archiving and processing system is programmed to send an alert signal when air quality data is outside defined operating parameters. The alert signal can be sent over the public communications network to one of the private communications networks or a remote site. The alert signal can be one or more of an e-mail message, an automated telephone message, an automated fax, or an automated pager message.
In another embodiment, the controller is programmed to calculate trends in air quality data. The archiving and processing system is programmed to send an alert signal when a calculated trend predicts that air quality data will be outside defined operating parameters within a defined time interval.
The present invention is also directed to a method for monitoring air quality comprising the steps of coupling one or more sensor assemblies programmed to collect air quality data to a private communications network located at a site. The level of one or more air quality attributes is measured using air quality sensors in the sensor assemblies. The sensor data is converted to air quality data. The air quality data is uploaded to the private communications network. The air quality data is transmitted over a public communications network to a second private communications network. The air quality data from one or more sensor assemblies is automatically stored in a database on the second private communications network. Access to the air quality data in the database is provided through the public communications network.
The present invention is also directed to a sensor assembly for use at a site having a private communications network that is adapted to carry data traffic. The sensor assembly includes at least one air quality sensor adapted to measure a level of an air quality attribute. A microprocessor is coupled to the air quality sensor and to a data storage device. The microprocessor is programmed to convert sensor data to a protocol compatible with the private communications network. A communications device couples the microprocessor to the private communications network.
The present invention is also directed to a sensor assembly for use at a site having an HVAC controller that is adapted to control HVAC equipment in response to environmental conditions. The sensor assembly includes at least a first air quality sensor and a second air quality sensor each adapted to measure a level of at least one air quality attribute. A microprocessor is coupled to the air quality sensors and to a data storage device. The microprocessor is programmed to convert sensor data to a protocol compatible with the HVAC controller. The microprocessor is also programmed to adjust sensor data from the first air quality sensor in response to sensor data collected by the second air quality sensor. A communications device couples the microprocessor to the HVAC controller.
In various embodiments, the microprocessor can be programmed to modify an error correction table or run an error correction algorithm for the first air quality sensor in response to sensor data from the second air quality sensor. In another embodiment, the air quality data from the first air quality sensor is modified in response to temperature data above or below a temperature threshold. In yet another embodiment, the microprocessor is coupled to the HVAC controller through a private communications network.